LMR23630FQDRRRQ1 - 36V 3A Sync Step-Down Converter | TI
MPN: LMR23630FQDRRRQ1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.97 | $2.97 |
| 10 | $2.72 | $27.20 |
| 100 | $2.31 | $231.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.78 | $1,780.00 |
| 3,000 | $1.55 | $4,650.00 |
LMR23630FQDRRRQ1 Overview
What is a synchronous buck converter? A buck converter is a switched-mode power supply (SMPS) topology that steps a higher DC input voltage down to a lower regulated DC output by alternately switching an inductor between the input and ground. The 'synchronous' designation means the rectifier diode has been replaced with a second MOSFET to improve efficiency at high output currents. Within the broader power-management hierarchy, a buck converter sits below linear regulators (LDOs) for high-step-down / high-current applications because it dissipates far less power, but introduces switching ripple that must be filtered. The LMR23630-Q1 belongs to TI's SIMPLE SWITCHER family aimed at minimizing external component count.
Key features include 75 uA quiescent current (light load), peak-current-mode control for cycle-by-cycle current limit and simple loop compensation, precision enable pin with hysteresis for power sequencing, internal soft-start to limit inrush current, and thermal shutdown. The 12-pin WSON package exposes the die to a thermal pad with theta_JA of approximately 41 C/W on a standard JEDEC 4-layer board, supporting 3 A continuous output up to +125 C junction.
Architecture depth: the LMR23630-Q1 uses peak current mode control with internal slope compensation, an 80 mV typical current-sense threshold, and a 7 MHz capable error amplifier. The wide 200 kHz to 2.2 MHz RT-programmable switching range lets the designer trade efficiency against passive component size. Internally the high-side FET has 95 mΩ and low-side 70 mΩ typical RDS(on) at 12 V, achieving peak efficiencies above 90 % at 24 V to 5 V/3 A.
When designing with the LMR23630-Q1, choose the inductor so that its ripple current is between 20 % and 40 % of the 3 A output, place the input ceramic bypass within 5 mm of the PVIN pin, and follow the layout recommendations in the manufacturer datasheet. A feedback resistor divider using 1 % parts sets VOUT; the F-variant fixed 400 kHz switching minimizes BOM for noise-sensitive automotive rails.
This page synthesizes distributor pricing, drop-in automotive alternatives from the LMR23610/15/25-Q1 family, and practical layout notes not found in the manufacturer datasheet alone.
Drop-in alternatives for LMR23630FQDRRRQ1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LMR23630QDRRRQ1
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LMR23625QDRRRQ1
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LMR23615QDRRRQ1
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LMR23630FQDRRRQ1 Maximum Ratings & Electrical Characteristics
| Topology | Synchronous Buck (Step-Down) |
| Input Voltage Range | 4 V to 36 V |
| Output Voltage Range | 1 V to 28 V (Adjustable) |
| Continuous Output Current | 3 A |
| Switching Frequency | 200 kHz to 2.2 MHz (F-variant fixed at 400 kHz) |
| Quiescent Current | 75 uA (typ) |
| Control Mode | Peak Current Mode |
| High-Side RDS(on) | 95 mΩ (typ at 12 V) |
| Low-Side RDS(on) | 70 mΩ (typ at 12 V) |
| Operating Temperature Range | -40 C to +125 C (Junction) |
| Package | 12-WFDFN Exposed Pad (WSON / DRR) |
| Mounting Type | Surface Mount |
| MSL Level | 2 (1 year floor life) |
| RoHS Status | Compliant |
| AEC-Q100 Qualification | Qualified (Automotive Grade) |
| Enable Pin | Yes (precision, with hysteresis) |
| Soft-Start | Internal |
| Thermal Shutdown | Yes |
LMR23630FQDRRRQ1 Pin Configuration
| Pin 1 | PGND — Power ground return for low-side FET |
| Pin 2 | PVIN — Power input supply to high-side FET |
| Pin 3 | PVIN — Power input supply to high-side FET (duplicate) |
| Pin 4 | SW — Switch node - inductor connection |
| Pin 5 | SW — Switch node - inductor connection (duplicate) |
| Pin 6 | BST — Bootstrap supply for high-side gate driver |
| Pin 7 | PGND — Power ground return (duplicate) |
| Pin 8 | AGND — Analog ground reference |
| Pin 9 | FB — Feedback voltage input (VOUT sense, internal 1 V ref) |
| Pin 10 | RT — Resistor timing - sets switching frequency (F variant: NC internally) |
| Pin 11 | EN — Precision enable input with internal pull-up |
| Pin 12 | PGOOD — Power-good open-drain output |
Typical Applications
LMR23630FQDRRRQ1 is suitable for 6 applications: Automotive 12 V Battery Rail Conditioning, Industrial 24 V / 28 V Bus Power Supplies, Portable Battery-Powered Equipment, PLC and Factory Automation I/O, Building Automation and HVAC Control, General-Purpose Point-of-Load (POL) Regulation.
Automotive 12 V Battery Rail Conditioning
The LMR23630FQDRRRQ1 is purpose-built for automotive 12 V battery rail conditioning, accepting 4 V to 36 V input to handle cold-crank (down to 4 V) and load-dump transients (up to 36 V) without damage. Its 3 A continuous output current and 400 kHz fixed switching frequency generate clean 5 V or 3.3 V rails for body electronics, infotainment controllers, and ADAS sensor modules. The internal synchronous FETs achieve >90 % efficiency at 12 V to 5 V / 2 A, eliminating the need for an external Schottky diode and shrinking the BOM versus older non-synchronous buck regulators. AEC-Q100 qualification makes it directly suitable for under-hood and cabin ECUs in production vehicles.
Recommended
Industrial 24 V / 28 V Bus Power Supplies
For industrial 24 V and 28 V bus systems, the LMR23630FQDRRRQ1's 36 V input withstand rating comfortably exceeds the highest expected bus voltage plus transients. The adjustable 1 V to 28 V output range lets a single part serve multiple rail requirements - 24 V pass-through, 12 V intermediate, 3.3 V logic - by changing only the feedback resistor divider. At 24 V to 5 V / 3 A, the synchronous topology sustains ~92 % efficiency, reducing heatsinking needs in sealed industrial enclosures. The 400 kHz fixed switching node makes output LC filter design straightforward and avoids interference with low-frequency industrial sensor bands.
Recommended
Portable Battery-Powered Equipment
In portable and battery-powered applications, the LMR23630FQDRRRQ1's 75 uA quiescent current minimizes standby drain, extending battery life when the load is asleep. Its 4 V minimum input allows operation directly from a single lithium-ion cell (3.0 V to 4.2 V) with a boost front-end or from 2S / 3S alkaline packs. Synchronous rectification eliminates the reverse-recovery losses of a Schottky diode, important at low VIN where every millivolt matters. The 4 mm x 4 mm WSON footprint suits handheld test instruments, portable medical monitors, and field-deployed IoT gateways where PCB real estate is scarce.
Recommended
PLC and Factory Automation I/O
PLC digital-output modules and factory-automation I/O subsystems benefit from the LMR23630FQDRRRQ1's combination of wide input range, 3 A output, and AEC-Q100 robustness. The synchronous topology holds output ripple below 30 mVpp at full load, preventing logic-level glitches on 24 V-to-5V/3.3 V rails that drive optocouplers, RS-485 transceivers, and digital I/O expanders. The internal peak-current-mode control with cycle-by-cycle current limiting protects downstream components from short-circuit events typical of industrial wiring faults. The exposed thermal pad handles sustained 3 A operation in sealed DIN-rail enclosures without external heatsinking.
Recommended
Building Automation and HVAC Control
Building automation controllers and HVAC systems running on 24 VAC rectified DC bus benefit from the LMR23630FQDRRRQ1's 36 V tolerance, which survives rectified 24 VAC peaks of ~34 V plus margin. The 3 A output powers relays, TRIAC drivers, communication modules, and main MCU rails from a single converter. AEC-Q100 qualification provides extra reliability margin for 10+ year installed lifetimes in commercial HVAC equipment. The fixed 400 kHz switching frequency simplifies EMI compliance for FCC Part 15 / EN 55011 conducted emissions in building-automation products.
Recommended
General-Purpose Point-of-Load (POL) Regulation
As a point-of-load (POL) regulator for downstream FPGAs, ASICs, and microcontrollers, the LMR23630FQDRRRQ1 steps a 12 V or 24 V intermediate bus down to a local 1.0 V to 5.0 V core rail. Its 400 kHz switching frequency keeps the output LC filter small, while the synchronous topology preserves >90 % efficiency even at 2-3 A loads typical of SoC rails. The adjustable output range covers nearly all common digital supply voltages without changing the converter, and the precision enable with hysteresis supports sequenced multi-rail power-up demanded by modern processors.
Recommended
Recommended Products Summary
Engineering reference data for LMR23630FQDRRRQ1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LMR23630QDRRRQ1 | LMR23630FDRRR | LMR23625QDRRRQ1 | LMR23615QDRRRQ1 |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 12-WSON DRR (4x4 mm) | 12-WSON DRR - same | 12-WSON DRR - same | 12-WSON DRR - same | 12-WSON DRR - same |
| Output Current | 3 A | 3 A | 3 A | 2.5 A | 1.5 A |
| Input Voltage Range | 4 V to 36 V | 4 V to 36 V | 4 V to 36 V | 4 V to 36 V | 4 V to 36 V |
| Switching Frequency | 400 kHz (fixed, F variant) | 200 kHz-2.2 MHz (RT-programmable) | 400 kHz (fixed) | 200 kHz-2.2 MHz (RT-programmable) | 200 kHz-2.2 MHz (RT-programmable) |
| AEC-Q100 Qualification | Yes | Yes | No (commercial grade) | Yes | Yes |
| Quiescent Current | 75 uA | 75 uA | 75 uA | 75 uA | 75 uA |
| Approximate 1k Price (USD) | $1.78 | $1.78 | $1.65 | $1.55 | $1.40 |
Key Differentiators
- Fixed 400 kHz switching frequency simplifies automotive EMI compliance (vs LMR23630QDRRRQ1)
- AEC-Q100 qualified for automotive deployment (vs LMR23630FDRRR)
- Higher 3 A continuous output current vs lower-tier family members (vs LMR23625QDRRRQ1)
Design Notes
Estimated: For a 24 V to 5 V / 3 A application, the LMR23630FQDRRRQ1 dissipates roughly (24 V - 5 V) * 3 A * (1 - 0.92) = 4.6 W. Use at least 1 square inch of 2 oz inner-plane copper tied to the exposed thermal pad with a 5x5 via array of 0.3 mm holes for the WSON-12 package. Place the input 10 uF X7R ceramic bypass capacitor within 5 mm of the PVIN pin and use a 22 uF output ceramic to minimize ripple. Keep the SW node traces short and surrounded by PGND copper to reduce radiated EMI.
Do not leave the EN pin floating - although it has an internal pull-up, leaving it unconnected can cause undefined startup behavior with unpredictable power sequencing. Tie EN to PVIN through a 100 kΩ resistor for always-on operation, or to a logic-level control signal for sequenced startup. Also, do not exceed the BST-to-SYNC voltage of 6 V - the bootstrap capacitor must be a 0.1 uF X7R ceramic rated for at least 10 V, located within 2 mm of the BST and SW pins.
The 400 kHz fixed switching frequency of the LMR23630FQDRRRQ1 sits in a CISPR 25 automotive EMI band 2 region; shield the SW node with PGND copper pour on both top and inner layers, and use a pi-filter (input ferrite bead + 10 uF / 1 uF ceramics) on the input to pass conducted emissions tests. Adding a small 10 nF bootstrap series resistor on BST can reduce high-frequency ringing that often fails automotive radiated EMI scans. The exposed thermal pad must be soldered completely - any voids raise junction temperature and reduce EMI margin.
Compliance Information
AEC-Q100 qualified for automotive applications per TI LMR23630-Q1 product page. RoHS and REACH compliant per TI product specifications. Choose commercial LMR23630FDRRR variant for non-automotive end products to avoid unnecessary AEC-Q100 cost premium.
